1. Field of the Invention
The present invention relates to a wireless local access network (WLAN), and more particularly, to a procedure of setting up a mesh peer link in a wireless mesh network and a wireless station supporting the procedure.
2. Description of the Related Art
With the recent development of information communication technology, a variety of wireless communication technology has been developed. A WLAN is the technology permitting wireless access to Internet in home or companies or specific service areas by the use of portable terminals such as a personal digital assistant (PDA), a laptop computer, and a portable multimedia player (PMP) on the basis of a radio frequency technology.
The IEEE (Institute of Electrical and Electronics Engineers) 802 which is a standardization of the WLAN technology established in February, 1980 has carried out much standardization work. In the initial WLAN technology, a data rate of 1 to 2 Mbps was supported by the use of frequency hopping, spread spectrum, and infrared communication using a frequency of 2.4 GHz in accordance with the IEEE 802.11. In recent years, 54 Mbps in maximum can be supported by the use of the orthogonal frequency division multiplex (OFDM) technology to the WLAN. In addition, the IEEE 802.11 has developed or is developing a variety of technical standards for improvement in quality of service (QoS), compatibility of an access point (AP) protocol, security enhancement, wireless resource measurement, wireless access in vehicular environment, fast roaming, wireless mesh network, inter-working with external networks, wireless network management, and the like.
The “wireless mesh network” can support direct communication between plural wireless stations having a relay function. In view of functionality, a distribution system (DS) for plural APs can be replaced with an inter-operable wireless link or a multi-hop path between the plural wireless stations. In the mesh network, one wireless station can set up a peer-to-peer wireless link with one or more neighboring wireless stations, thereby constructing a more flexible network.
In the wireless mesh network, one wireless station can establish plural peer links with each of other wireless stations. Thus, plural communication paths can exist between two wireless stations. Among them, the direct communication paths between two wireless stations are called a wireless mesh link or a mesh peer link or a peer link. The wireless stations are called mesh points (MP), which is only an example. A wireless station performing the function of an AP is called mesh access point (MAP).
Such a wireless mesh network has advantages such as flexibility in constructing a network, reliability due to bypass paths, reduction in power consumption due to a decrease in communication distance. More specifically, it is possible to construct a flexible network by using the mesh network even in places not including any wired communication network. In the mesh network, the plural MPs can be connected to each other to guarantee plural bypass paths. Accordingly, even when one MP is out of order, data can be transmitted through another path. In the mesh network, since the communication can be made through a neighboring MP, it is possible for terminals to communicate with low power.
On the other hand, the IEEE 802.11n is a technical standard made in relatively recent years to overcome the limit in communication speed, which is a weak point of the WLAN. The IEEE 802.11n is designed to enhance the speed and reliability of the network and to extend the operating coverage of the wireless network. More specifically, the IEEE 802.11n supports high throughput (HT) in which the data processing rate is 54 Mbps in maximum and is based on the MIMO (Multiple Inputs and Multiple Outputs) technology employing multiple antennas at the transmitter and/or the receiver to minimize transmission errors and to optimize the data rate. The standard employs a coding scheme in which several copies are transmitted to enhance the reliability of data and may employ the orthogonal frequency division multiplex (OFDM) scheme to enhance the speed.